Pregnancy is one of the most exciting times in a woman's life, and for most of us, the challenges are comparatively minor: a few months of morning sickness, some bouts of hormone-fueled emotional upheaval. But what happens if the unthinkable occurs and you're hit with a truly life-changing event while you're expecting your baby?

Take, for instance, Sarah Ewald, now 37, who was 11 weeks pregnant and married to a man she believed to be her soul mate. Then, her husband, Kyle, a truck driver, was killed when his rig overturned in a freak accident. Or consider Alicia Varinaitis-Kunerth who, at age 30, was eight months into a blissfully healthy pregnancy when she suddenly began having seizures. A few days later, her doctor diagnosed her as having a malignant brain tumor.

Despite the seriousness of their circumstances, Ewald and Varinaitis-Kunerth--and many women like them--found the strength and resources they needed to face their crises, deliver and care for their babies, then begin to rebuild their lives. Varinaitis-Kunerth credits a combination of herbs, diet, acupuncture and meditation with aiding her through the radiation treatment that helped beat her cancer into remission. Ewald says that it was the support of close friends, her religious faith and knowing she was carrying Kyle's son that allowed her to move on when going on sometimes seemed impossible.

We found many other courageous mothers with stories of their own pregnancy crisis, four of whom are profiled here. We think you'll find that the ways in which each of them got through the toughest days of their lives offers inspiration to cope with unexpected challenges--pregnant or not--when life pushes you to extremes.

Even the way Kellie Mathas got pregnant was idyllic. "On my 34th birthday, in December 2004, I released a red balloon and wished that I'd conceive," she says. "And by Jan. 6, I had a positive pregnancy test." At the time, Mathas and her husband of 12 years, Allen, had good jobs (he was a marketing analyst, she an event planner) and lived in a pleasant upscale house 20 minutes from downtown New Orleans.

Mathas' baby was due in early September, and Saturday morning, Aug. 27, Mathas and her husband woke up to learn that a huge hurricane was coming their way.

The hurricane, of course, was Katrina. On Sunday, Mathas was having mild contractions, so she and her husband boarded up their house and headed for New Orleans. "My mother has an office in a building connected to Memorial Medical Center, so we figured we'd camp out there for a few days," she says. That night, the hurricane hit. "The building began to shake and rock, and the wind was like nothing we'd ever seen," Mathas recalls. "We never thought we'd survive."

By Monday afternoon, they assumed the worst was over. "No one knew that the levees had been breached," Mathas says. Soon, the backup generators failed, the temperature shot up over 100 degrees, and Mathas began to dehydrate. "I kept thinking, this must be what hell feels like," she says.

And then the water began to rise. By midday Tuesday, the medical center was all but cut off, and temperatures inside soared to 110 degrees. (Forty-five people would eventually die there.) Mathas and her husband saw no choice but to make a desperate drive to Baton Rouge where there were still functioning hospitals. "It's still hard for me to talk about," Mathas says. "When we drove, it was a scene out of 'War of the Worlds.'"

Miraculously, they arrived in Baton Rouge unscathed, and on Monday, Sept. 5--Labor Day--Cole McGregor was born. The next day, Mathas and her husband checked on their house, found it still standing, then returned to the hospital. They stayed in Baton Rouge and didn't go home for a month. In the meantime, Mathas was slammed by a killer combination of postpartum depression and post-traumatic stress disorder.

Now, Mathas says, she is starting to heal with the help of a psychiatrist and a therapist, twice-daily long walks and reaching out to mothers who have dealt with similar traumas. "It really helped me to talk to women who'd been through postpartum depression," she says. "They helped me know I was going to get better." Mathas says she's also hoping to find or form a support group for women who gave birth during or after Katrina. "There are a lot of scared women right now in New Orleans," she says. "Our city is still devastated, and it's taking all of us a while to recover."

Jennifer Gillette, 29 Hillsboro, Ore.Mother of William, 11 months. Abandoned by her husband when she was five months pregnant.

In January 2005, Jennifer Gillette figured her life was just about perfect. She was five months pregnant with her first child, had a great job as a graphic designer and was married to a man she loved and who, as far as she knew, loved her back. But then, her husband, Reed, dropped the bomb: He was unhappy and wanted to divorce.

"I was completely blindsided," Gillette says. "I honestly had no clue. I thought we were happy." At first, Reed's complaints were vague. So, determined to save the marriage, Gillette suggested counseling. But she mostly ended up going alone. Eventually, the truth came out: There was another woman.

Reeling from grief and hormone-fueled emotions, Gillette confided only in her therapist. "I couldn't even acknowledge it to myself, much less tell my friends," she says. "I was so humiliated." Instead, she cried all the way to work, "then all the way through lunch, sitting in my cubicle," and all the way home. "And then I'd cry until I went to bed."

Gillette's emotional turning point came when she began sobbing in her prenatal-exercise class. "I completely lost it," she says. When her trainer asked what was wrong, Gillette blurted everything out. "Hey," the trainer replied. "My husband took off when my baby was a newborn. It's terrible, but you'll get through it." That conversation made Gillette realize it was time to start building a support network.

"I began by picking two women at my office and reaching out to them," she says. "Women are amazing, and when you open up to them, they'll share the most awesome stories of their own." Gillette also hired a doula to give her emotional support during labor and delivery. "Asking for help was really big for me," she says. "But I found that nobody can help unless you tell them what you need."

Now, Gillette says, she's finding joy in single motherhood. "I knew I had to take care of my baby, and that meant I had to take care of myself," she says. "Things aren't perfect yet, but they're good, especially when I look into my son's face."

Frances Macias-Aguilar, 33 Los AngelesMother of Estephanie, 15, George, 14, Julian, 10, Frankie, 6, Elijah, 4, and Gennisis, 2. Had to work to clear her husband of a false arrest charge while pregnant with her sixth child.

When Frances Macias-Aguilar learned she was having a sixth baby, she was sure this pregnancy would finally be a secure and happy one. Raised by a troubled single mother in a poor and gang-ridden area of East Los Angeles--herself a mother to five kids by the time she turned 30--Macias-Aguilar had worked diligently to transcend her difficult past.

Both she and her husband, Luis, had been gang members as teenagers. But now they were building decent, new lives. Luis had an excellent union job doing construction for the city of Los Angeles, and Macias-Aguilar worked for Homeboy Industries, a gang-intervention program where she helped find jobs for young people with pasts similar to her own. When she and Luis decided to have one more baby, they did so as an act of faith in their hard-won future.

Macias-Aguilar knew from the ultrasound that the baby was a girl. "We decided to name her Gennisis, like the first book of the Bible," she says, "only with a different spelling. Because we knew this little girl would symbolize our new beginning." The baby was due Feb. 22, 2004. On Jan. 23, Macias-Aguilar came home to find her front door bashed off its hinges, the interior of her home hit by what appeared to be a cyclone. The police had raided her house and arrested Luis for drug sales.

Macias-Aguilar fought not to panic. "Suddenly, I had nobody to go with me to doctors' appointments, nobody to help with the kids, and how would we get by without Luis' salary?" she says. Also, there was the terror of her husband's legal situation. "I knew he didn't do what they were saying," she says. "But when you're a former gang member, no one wants to believe you can change." So in addition to everything else, Macias-Aguilar began to investigate her husband's case.

Gennisis Angelina was born on Feb. 29--a leap-year baby. Due in part to Macias-Aguilar's efforts, the case against Luis was dropped in its entirety six months later. In between, Macias-Aguilar says, she relieved her crushing stress through the help of friends (including the co-workers who gave her a giant surprise baby shower), by taking power walks around the local park and by helping to form a local women's support group. "People who know my story often ask me how I got through it," she says. "I just tell them, 'Women are strong. We do what we have to do, right?' "

Mary Hackett, 30 CincinnatiMother of Brigid, 6; and Colm, 4 months. Survived a violent rape, then became a single mother over her family's objections.

In August 1998, Mary Hackett, then 22, was driving from her family's home in Connecticut to the University of Nebraska, where she was getting her master's degree in English. Her car broke down, and she rented another during the repair. When Hackett returned the car, the rental agent raped her so violently that, although she didn't know it, she sustained serious internal injuries. But Hackett went back to school, telling few people about the rape until her untreated injuries sent her to the hospital with septic shock and a high fever.

Normally a self-sufficient high achiever, Hackett fell apart. "I lost sight of what I wanted in life, my goals, everything," she says. Longing for some kind of comfort, she began seeing a young man. "I was so desperate and so alone," she says. "And here was this sweet guy I thought was going to save me."

Within months, Hackett was pregnant. Her parents suggested adoption, but later accepted her decision to keep the baby; the baby's father and his parents wanted her to "get rid" of it. Hackett refused. "I knew I loved my baby. Even though I had no one else to rely on, and sometimes I barely had enough to eat, I knew I'd somehow find a way to raise her," she says.

The decision resulted in further condemnation. "Suddenly, everybody--including some members of my own family--kept saying I was this horribly irresponsible person who was ruining everyone else's life." She was working three jobs, and to keep herself sane, she did yoga at home and joined a prenatal support group. "I also got one-on-one therapy," she says. "But mostly, I just made the mental decision that I was going to make it come hell or high water, no matter what people said."

A month after finishing her master's program, Hackett moved back to Connecticut and gave birth to an 8-pound, 8-ounce girl. "I had to go back to work two days after she was born," she says. "For the first year, I worked three jobs because day care was so expensive."

Today, Hackett is married to an architect, Greg, and the two recently had a child together. "So I guess you could say it worked out after all," she says. "I have a wonderful marriage, job and children. It just goes to show you, if believe you can do it, chances are you can."